INSTRUCTIONS TO MARINE METEOROLOGICAL OBSERVERS 3 



Office. The number of ships that are authorized to send daily reports 

 by radio is limited by the funds available for payment of radio and 

 telegraph tolls, because the observations are sent at Government 

 expense. The chief considerations in selecting a ship for radio re- 

 porting are, first, whether the ship's usual route is likely to result in 

 reports from areas where observations are needed; second, whether 

 the ship has long-range radio equipment that will insure transmis- 

 sion to shore radio stations from the distant and less traveled areas 

 where there is often a scarcity of radio reports. For these reasons, 

 the shipmaster should not begin forwarding daily reports by radio 

 until he has first consulted the Weather Bureau. However, radio 

 reports are desired from any ship when an intense storm, particu- 

 larly one of tropical origin, is encountered. 



Instruments. — Since the essential meteorological instruments, the 

 barometer and thermometer, form a part of the equipment of every 

 T^ell-found vessel, the Weather Bureau does not, as a regular pro- 

 gram, provide marine observers with instruments. It does recom- 

 mend, however, that instruments recognized to be of reliable manu- 

 facture be used, that they be properly exposed on shipboard, and 

 that barometers, in particular, be regularly compared with standard 

 instruments of the Weather Bureau or some other national meteoro- 

 logical organization. Advice regarding the specifications for instru- 

 ments to be purchased will be gladly furnished by Weather Bureau 

 officials, and instruments will be tested at time of purchase if desired. 



Forwarding reports hy mail.— It is highly desirable that reports be 

 forwarded promptly by mail at the end of each voyage, or upon 

 arrival at a port of call if the voyage be a long one. The mail re- 

 ports are used in writing monthly summaries of weather conditions 

 over the oceans and in preparing accounts, including tracks, of un- 

 usual storms for publication. The material goes to press regularly 

 at the close of the month following that in wdiich the weather con- 

 ditions are experienced and recorded, hence early receipt of the re- 

 ports is very helpful. This applies also to ships that report by 

 radio. The observations on forms sent by mail contain more detailed 

 information than the radio messages; furthermore, mistakes some- 

 times occur in transmission by radio and telegraph; hence the mail 

 forms make corrections possible. 



Mail reports should be inclosed in envelopes provided by the 

 Weather Bureau. In a foreign port, the envelopes should be ad- 

 dressed to the United States Weather Bureau, Washington, D. C, 

 and handed to the United States Consul, who is under instructions 

 to forward them with his official mail, free of expense. If the re- 

 ports are put directly in the mail at any port outside of the United 

 States and its possessions, postage is necessary at regular letter rates. 

 Franked envelopes do not require postage when mailed in the United 

 States, Hawaii, the Philippines, Puerto Rico, Panama (Canal Zone), 

 Virgin Islands, Guam Island, Tutuila Island, or Midway Island. 



Pilot charts. — Monthly pilot charts of the North Atlantic, North 

 Pacific, and Indian Oceans, and Central American waters, and 

 quarterly charts of the South Atlantic and South Pacific Oceans 

 are sent free to shipmasters who regailarly contribute data to the 

 Weather Bureau. The data appearing on the pilot charts are fur- 

 nished jointly by the United States Weather Bureau and the United 



